Shank and bit punch



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Patented Jan. 15, 1929.

UNITED STATES PATENT OFFICE.

JESSE DITSON, OF LITTLETON, COLORADO, ASSIGNOR TO INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION 0F NEW JERSEY.

SHANX AND BIT PUNCH.

Application led September 21, 1927. Serial No. 221,016.

Thisinvention relates to devices for reforming the bores of hollow articles, but more particularly to a fluid actuated device for pinning out hollow drill steels in whichthe ends of the bore frequently become restricted during the sharpening operation.

One object of the invention is to drive a punch pin into the bore of a drill steel and withdraw it therefrom by rapidly repeated blows of the hammer piston against lthe anvil block whereby the punch pin is carried.

Another object is to control the operation of the apparatus by forces, such as manual pressure, applied to the punch pin.

Other objects `will be in part obvious and in partl pointed out hereinafter.

In the drawings showing a preferred modilic-ation of the invention,

Figure l is a longitudinal sectional elevation of a shank and bitpunch constructed in accordance with the practice of the invention and showing the parts in position for driving the punch pin into the work, and

Figure 2 is a view similar to Figure l illustrating the position of the parts for withdrawing the punch pin from the work.

Referring to the drawings, A designates the cylinder of a shank and bit punch, and B the piston chamber in which is disposed a reciprocatory. hammer piston C. The cylinder A may be provided with any suitable means for securing the device to a support, such as a drill sharpener wherewith devices of the type described herein are usually associated. The means provided for this purpose in the present instance comprise flanges D which form a base for the cylinder A and through these flanges may extend bolts E on which are threaded nuts F to clamp the machine to a foundation The piston chamber B comprises an enlarged forward portion H and a rearward reduced portion J. The piston C is proportioned accordingly and its rearward reduced portion K in this instance is constantly eX- posed to pressure fluid during the operation of the machine as will be more fully described hereinafter.

Secured to the front end of the cylinder A is a front head L and between the front head L and the cylinder A is disposed a plate O having rearward and forward bosses P and Q which extend into the cylinder A and the front head L respectively for centralizing these parts with respect to each other. The

front head L and the plate O may be secured to the cylinder by means of bolts R screwed into the end of the cylinder.

Disposed at the rearward end of the cylinder A and securedthereto by bolts R is a valve chest S having a valve chamber T which in this instance is formed coaxially with the piston chamber B. A cover U forms a closure for the rearward end of the valve chamber and has a port V for the purpose of constantly maintaining atmospheric pressure in the rearward end of the valve chamber T.

Pressure fluid for actuating the piston C may be conveyed to the valve chest through a connection lV leading from a source of pressure fluid supply (not shown), and such pressure fluid may pass into the valve chamber T through a passage Xin the side of the valve chest S.

From the rearward end of the small portion J of the piston chamber B leads a passage Y to a point near the forward end of said small portion J for conveying pressure fluid to the rearward end of the enlarged portion H of the piston chamber to act,

against a rearward surface Z of the piston for impelling the piston C forwardly. The rearward end of the passage Y may be in constant communication with the pressure fluid supply and the exit end b of the passage `Y is in this instance controlled by a neck c formed on the reduced portion K of the piston adjacent the surface Z.

The pressure fluid-utilized. for driving the piston C in a rearwardly direction is conveyed into the front end of the piston chamber B by a passage cl which communicates at its rearward or entrance end e with the reduced portion J of the piston at a point intermediate the ends of the passage Y. The passage d in this instance is controlled by the reduced portion K of the piston C. A free exhause port F leads fromthe enlarged portion of the piston chamber H to the atmosphere for exhausting the pressure fluid from both ends of the enlarged portion H, said exhaus` port f being controlled only by the piston l. f

Extending slidablythrough the front head, the cylinder and the piston, is an anvil block g having a recess h in its front end to receive a punch pin j of a well known type adapted to be driven into a hollow drill steel k. The punch pin j may be secured inthe anvil block g in any suitable manner, in the present instance a pin o extending transversely through the anvil block and the punch pin j is used for this purpose.

The forward end of the anvil block g c0- operates slidablywith a bore p in the front end of the front head L to support the anvil block at this point. Suitably spaced rearwardly of the enlarged portion g of the anvil bloclr is a collar Q against which the blows of the piston C maybe delivered whenever the anvil block fl is pushed in a rearwardly direction by pressure applied to the drill steel 7c.

The anvil block g is in this instance threaded as at r throughout a portion of its length rearwardly of the piston C to receive a nut s against which blows of tl e hammer piston C may be delivered for withdrawing the punch pin j from the drill steel 7c.

As will be observed the rearward end of the anvil block g entends into the valve chamber T and attached thereto is a throttle valve t slidable with the anvil block for controlling the admission of pressure fluid from the passage X into the valve chamber T.

The throttle valve t disclosed is in the form of a hollow sleeve and has a plurality of radial ports u intermediate its ends which, when the throttle valve tis in its forwardmost position, will register with the passageX tov admit pressure iiuid through the interior of the throttle valve t into the cylinder. Y

In order to render the connection between the throttle valve t and the anvil block g flexible, thus protecting the throttle valve 't against the effects of the jarsl and shocks of the hammer piston C, said throttle valve t is provided with an internal flange e which seats in a pair of grooved washers w, one of which is disposed on each side of the flange o. f

The washers u are disposed slidably on the end of the anvil block g and coil springs g/ act against the washers to cushion the movement of the throttle valve. A nut e screwed on the rearward end of the anvil block g bears again st the rearward spring jz/ and holds the throttle valve t and associated parts against removal from the anvil block.

Suitable means are provided for automatically closing the throttle valve t whenever the pressure whereby the anvil block g is actuated is removed therefrom. The means whereby this is brought about in the present instance comprise a compression spring 2 f. v seated with its forward end on split collars 3 which in turn may bear either against a shoulder i on the anvil bloclr or against the forward surface of a recesso in the front head L wherein the spring 2 is'disposed, depending upon theposition of the Aanvil block g.

Similar split washers 7 are provided for the rearward end of the spring 2 to-abut either the collar g or a shoulder 8 in the plate O.

The length of the recess 6 and the space between the collar g' and the shoulder 4L are preferablyT about the same so that when the anvil block g is in the intermediate position to which it will be moved by the spring 2, said spring mayI` exert a constant force or pressure on the shoulder 4 and the collar g to hold the anvil block g immovable in the cylinder.

The operation of the device briefly described is as follows: Let it be assumed that at the beginning of the operation, the anvil block g is in the intermediate position hereinbefore referred to and thus that the throttle valve tis in the closed position which it would then occupy. If then it be desired to drive the punch pin into the drill steel 7c the attendant may press said drill steel against the punch pin with suicient force to compress the spring 2 and move the throttle valve t rearwardly to the posit-ion illustrated in Figure 1. ln this position of the throttle valve, pressure fluid entering the rearward end of the small portion J of the piston chamber will flow through the passage Z to the front endof the cylinder and impel the piston C rearwardly.

After the piston has travelled rearwardly, a suiiicient distance to open the eXit Z) of the passage Y, pressure iuid will flow into the rearward end of the enlarged portion H of the piston chamber, and such pressure fluid, together with that acting against the rearward end of the portion K of the piston, will actuate the piston C forwardly against the collzltr g to drive the punch pin j into the drill stee The pressure fluid from both ends of the enlarged portion H will be exhausted through the exhaust port 7` as the piston C overruns said exhaust port. This cycle'of operations may be repeated as long as the anvil block g is pushed rearwardly to hold the valve 2f in its rearwardmost position.

After the punch pin y' has been driven. into the drill steel-7J'U as illustrated in Figure 2, the operator may, by pulling on the drill steel 7c, draw the anvil block g forwardly against the pressure of the spring 2 and thus withdraw the collar g out of the path of the'piston C and at the same time advance the nut s a sufficient distance to permit the blows of theV hammer piston C to be delivered thereon.

' As will be observed, when the anvil block g is pulled forwardly the valve t will occupy such a position that the ports u will be inV registry with the passage X v and pressure tluid will then flow through these ports and the front portion of the throttle valve t into the rearward end of the piston chamber, fromv whence it will be distributed to the ends of the enlarged portion H of the piston chamber in a well known manner. After the punch pin j has been loosened from the drill steel 7c the spring 2 will restore the anvil block g to its intermediate position and the forward imperforate portion of the throttle valve t will then cut 0H communication between the passage X and the percussive element of the device.

I claim:

1. In a shank and bit punch, the combination of a cylinder and piston, a punch pin, an anvil block carrying the pin and extending slidably through said piston to transmit the blows of the piston to the punch pin both for driving the punch pin into and out of an article intended t-o be punched, a throttle valve connected yieldably to the anvil block controlling the admission of pressure fluid into the cylinder, and a coil Spring exerting a force on the anvil block to restore said anvil block to an intermediate position and thus also to close the throttle valve.

2. In a shank and bit punch, the combination of a cylinder and piston, a punch pin, an anvil blodk carrying the pin and extending slidably through said piston to transmit the blows of the piston to the punch pin both for driving the punch pin into and out of an article intended to be punched, a throttle valve connected yieldably to the rearward end of specification.

JESSE DITSON. 

